How does this work exactly? I mean, WinUAE already had FPU emulation, but what is the difference for this? That it is implemented without using the host FPU? Is WinUAE even built towards non-FPU targets?

How does this work exactly? I mean, WinUAE already had FPU emulation, but what is the difference for this? That it is implemented without using the host FPU? Is WinUAE even built towards non-FPU targets?

You don't need to know

Seriously, it is 100% accurate and bit-perfect FPU emulation, emulation done fully in software which also makes it slower than "normal" FPU emulation that uses host FPU.

All the 6888x/68040/68060 differences are fully emulated in softfloat mode, including arithmetic exceptions (I still don't know any Amiga program that uses those..) and other special cases.